From the editorial “Communication Between Minds” by Fred Pohl [Worlds of Tomorrow, Nov 1965]
“Reading Vitus Droscher‘s fascinating The Mysterious Senses of Animals (Dutton), when it occurred to us that an experiment Droscher had described could be construed as a proof of telepathy. The experiments in question were performed by von Holst and Jechorek at the Max Planck Institute. The subjects were two chickens, connected by a wire and an amplifier that carried a current from the brain of one chicken to the brain of the other, via stereotaxically implanted electrodes. When the first chicken was exposed to the sight of a dog, the second chicken — completely out of sight and hearing, in another room — fluttered up the wall, squawking in alarm. Not telepathy?”